hanging scroll, width
幅 centers on the idea of lateral extent or a flat, spread-out surface: the width of something, or a hanging scroll that spreads across a wall.
幅 combines 巾 (cloth) with 畐, which likely contributes the sound and the idea of fullness or spreading out, suggesting a piece of cloth that extends in width.
The left side 巾 is cloth, and the right side 畐 looks like a full container. Picture a bolt of cloth unrolled to its full width, like a hanging scroll spreading across a wall.
For フク, imagine a wide hanging scroll with a picture of Mount Fuji (ふじ) on it: Fuji -> フク, and the scroll shows the mountain's full width.
width; breadth
big; large; drastic; substantial
extensive; wide; broad
amplification
shoulder width (breadth)
full; wholehearted; utmost; all; every
wide (e.g. belt, shoes, ribbon); broad
amplitude (of vibration)
width (of a road, bridge, etc.)
(length of one's) step; stride; pace
width of a road
long jump
small; narrow
widening (of a road)
amplifier
width of a river
price range or fluctuation
long jump; broad jump
large, broad-shouldered physique (esp. that of a middle-aged man); big build
width of a garment